On August 5, 2019, the German Federal Institute for Risk Assessment (BfR) published a press release announcing the results of an experimental study investigating the effects of polystyrene (PS; CAS 9003-53-6) microplastic exposure on intestinal tissue. The aim of the study was to examine the uptake and effects of microplastic generated from PS using two methods. Cultured human bowl tissue cells were first examined to see whether or not they take up PS microplastic with varying diameters (1, 4, and 10 µm). The study then used 28-day mice exposure tests to examine the transport of microplastic particles in the intestine and oxidative stress on intestinal immune cells. The study found “cellular uptake of a minor fraction of particles” and “absence of histologically detectable lesions and inflammatory responses” as well as no interference “with the differentiation and activation of the human macrophage model.” This led the authors to conclude that “oral exposure to PS microplastic particles under the chosen experimental conditions does not pose relevant acute health risks to mammals.”

Read more

BfR (August 5, 2019). “Keine Hinweise auf Darmschädigungen durch Mikroplastik aus Polystyrol im Labor.” (pdf) (in German)

Maria Delaney (August 20, 2019). “German researchers find polystyrene microplastic does not damage gut.” Chemical Watch


Stock et al. (2019). “Uptake and effects of orally ingested polystyrene microplastic particles in vitro and in vivo.” Archives of Toxicology (published May 28, 2019)